<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		* {
			margin: 0;
			padding: 0;
			list-style: none;
		}

		#box {
			width: 300px;
			height: 200px;
			border: 1px solid #ccc;
		}

		#ul {
			width: 300px;
			height: 50px;
		}

		#ul li {
			width: 98px;
			height: 48px;
			border: 1px solid #ccc;
			float: left;
			text-align: center;
			line-height: 48px;
		}

		#ul li.col {
			background: #ccc;
		}
	</style>
</head>

<body>
	<div id="box">
		<ul id="ul">
			<li class="col">111</li>
			<li>222</li>
			<li>333</li>
		</ul>

		<div id="bottom">111</div>
	</div>

	<script>
		var lis = [...document.querySelectorAll('#ul li')], //获取所有li
			bottom = document.querySelector('#bottom'), //获取下面盒子
			currentIndex = 0;

		//给所有li绑定事件

	</script>
</body>

</html>